package com.t.emlearn.ui.view;


import android.content.Context;
import android.database.DataSetObserver;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListAdapter;
import android.widget.Scroller;

import com.hyphenate.util.EMLog;
import com.t.emlearn.Constant;
import com.t.emlearn.EmLearnHelper;
import com.t.emlearn.utils.SysUtil;

import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.Queue;

/**
 * 成员List
 */

public class MemberListView extends AdapterView<ListAdapter> {
    private final String TAG = this.getClass().getSimpleName();

    protected MemberListViewAdapter mAdapter;
    private int mLeftViewIndex = -1;
    private int mRightViewIndex = 0;
    protected int mCurrentX;
    protected int mNextX;
    private int mMaxX = Integer.MAX_VALUE;
    private int mDisplayOffset = 0;
    protected Scroller mScroller;
    private GestureDetector mGesture;
    private Queue<View> mRemovedViewQueue = new LinkedList<View>();
    private OnItemSelectedListener mOnItemSelected;
    private OnItemClickListener mOnItemClicked;
    private OnItemLongClickListener mOnItemLongClicked;
    private boolean mDataChanged = false;
    private List<Integer> mListWidth;
    private int mMaxWidth = 0;
    private Context mContext;
    private int winWidth = 0;

    public MemberListView(Context context, AttributeSet attrs) {
        super(context, attrs);
        mContext = context;
        winWidth = SysUtil.getW(mContext);
        mAdapter = new MemberListViewAdapter(context);
        mAdapter.registerDataSetObserver(mDataObserver);
        initView();
    }

    private synchronized void initView() {
        mLeftViewIndex = -1;
        mRightViewIndex = 0;
        mDisplayOffset = 0;
        mCurrentX = 0;
        mNextX = 0;
        mMaxX = Integer.MAX_VALUE;
        mScroller = new Scroller(getContext());
        mGesture = new GestureDetector(getContext(), mOnGesture);
        mListWidth = null;
        mMaxWidth = 0;
    }

    @Override
    public void setOnItemSelectedListener(
            OnItemSelectedListener listener) {
        mOnItemSelected = listener;
    }

    @Override
    public void setOnItemClickListener(OnItemClickListener listener) {
        mOnItemClicked = listener;
    }

    @Override
    public void setOnItemLongClickListener(
            OnItemLongClickListener listener) {
        mOnItemLongClicked = listener;
    }

    private DataSetObserver mDataObserver = new DataSetObserver() {

        @Override
        public void onChanged() {
            synchronized (MemberListView.this) {
                mDataChanged = true;
            }
            invalidate();
            requestLayout();
        }

        @Override
        public void onInvalidated() {
            reset();
            invalidate();
            requestLayout();
        }

    };

    @Override
    public MemberListViewAdapter getAdapter() {
        return mAdapter;
    }

    @Override
    public void setAdapter(ListAdapter listAdapter) {

    }
    public void addMemberView(MemberView mv){
        this.mAdapter.addMemberView(mv);
    }

    public void addTeacherMemberView(boolean isLocal){
        MemberView mv = new MemberView(this.getContext());
        mv.setKey(Constant.KEY_MEMBER_LIST);
        mv.setName(EmLearnHelper.getInstance().getConferenceSession().getNickName());
        if(isLocal){
            mv.setLocal();
        }
        mv.setTeacher();
        this.mAdapter.addMemberView(mv);
    }

    public void addLocalMemberView(){
        MemberView mv = new MemberView(this.getContext());
        mv.setKey(EmLearnHelper.getInstance().getConferenceSession().getUserName());
        mv.setName(EmLearnHelper.getInstance().getConferenceSession().getNickName());
        mv.setStudent();
        mv.setLocal();
        this.mAdapter.addMemberView(mv);
    }

    public MemberView getMemberView(String key){
        return this.mAdapter.getItem(key);
    }

    @Override
    public View getSelectedView() {
        // TODO: implement
        return null;
    }


    private synchronized void reset() {
        initView();
        removeAllViewsInLayout();
        requestLayout();
    }

    @Override
    public void setSelection(int position) {
        try{
            // TODO: implement
            mListWidth = new ArrayList<Integer>(this.getChildCount());
            mMaxWidth = 0;
            for(int i=0; i<this.getChildCount(); i++){
                mListWidth.add(this.getChildAt(i).getWidth());
                mMaxWidth += this.getChildAt(i).getWidth();
            }
            int positionStart = 0;
            int currentWidth = 0;
            if(position > 0){
                for(int i=0; i<position && i<mListWidth.size(); i++){
                    positionStart += mListWidth.get(i);
                }
                currentWidth = this.getChildAt(position).getWidth();
            }
//		int maxWidth = this.getChildCount() * this.getWidth();
            if (positionStart <= 0) {
                positionStart = 0;
            }
            if (positionStart > mMaxWidth) {
                positionStart = mMaxWidth;
            }
            int pos = (positionStart - winWidth/2 + currentWidth/2);
            int scroll = 0;
            if(pos > 0)
                scroll = pos;
            else
                scroll = 0;
            scrollTo(scroll);
            EMLog.d(this.getClass().getName()
                    , "pos="+pos + ",position="+position
                            + ",positionStart=" + positionStart + ",currentWidth=" + currentWidth + ",scroll=" + scroll);
        }catch(Exception e){
            EMLog.e(TAG, e.getMessage());
        }
    }

    private void addAndMeasureChild(final View child, int viewPos) {
        LayoutParams params = child.getLayoutParams();
        if (params == null) {
            params = new LayoutParams(LayoutParams.FILL_PARENT,
                    LayoutParams.FILL_PARENT);
        }

        addViewInLayout(child, viewPos, params, true);
        child.measure(
                MeasureSpec.makeMeasureSpec(getWidth(), MeasureSpec.AT_MOST),
                MeasureSpec.makeMeasureSpec(getHeight(), MeasureSpec.AT_MOST));
    }

    @Override
    protected synchronized void onLayout(boolean changed, int left, int top,
                                         int right, int bottom) {
        super.onLayout(changed, left, top, right, bottom);

        if (mAdapter == null) {
            return;
        }

        if (mDataChanged) {
            int oldCurrentX = mCurrentX;
            initView();
            removeAllViewsInLayout();
            mNextX = oldCurrentX;
            mDataChanged = false;
        }

        if (mScroller.computeScrollOffset()) {
            int scrollx = mScroller.getCurrX();
            mNextX = scrollx;
        }

        if (mNextX <= 0) {
            mNextX = 0;
            mScroller.forceFinished(true);
        }
        if (mNextX >= mMaxX) {
            mNextX = mMaxX;
            mScroller.forceFinished(true);
        }

        int dx = mCurrentX - mNextX;

        removeNonVisibleItems(dx);
        fillList(dx);
        positionItems(dx);

        mCurrentX = mNextX;

        if (!mScroller.isFinished()) {
            post(new Runnable() {
                @Override
                public void run() {
                    requestLayout();
                }
            });

        }
    }

    private void fillList(final int dx) {
        int edge = 0;
        View child = getChildAt(getChildCount() - 1);
        if (child != null) {
            edge = child.getRight();
        }
        fillListRight(edge, dx);

        edge = 0;
        child = getChildAt(0);
        if (child != null) {
            edge = child.getLeft();
        }
        fillListLeft(edge, dx);

    }

    private void fillListRight(int rightEdge, final int dx) {
        while (rightEdge + dx < getWidth()
                && mRightViewIndex < mAdapter.getCount()) {

            View child = mAdapter.getView(mRightViewIndex,
                    mRemovedViewQueue.poll(), this);
            addAndMeasureChild(child, -1);
            rightEdge += child.getMeasuredWidth();

            if (mRightViewIndex == mAdapter.getCount() - 1) {
                mMaxX = mCurrentX + rightEdge - getWidth();
            }

            if (mMaxX < 0) {
                mMaxX = 0;
            }
            mRightViewIndex++;
        }

    }

    private void fillListLeft(int leftEdge, final int dx) {
        while (leftEdge + dx > 0 && mLeftViewIndex >= 0) {
            View child = mAdapter.getView(mLeftViewIndex,
                    mRemovedViewQueue.poll(), this);
            addAndMeasureChild(child, 0);
            leftEdge -= child.getMeasuredWidth();
            mLeftViewIndex--;
            mDisplayOffset -= child.getMeasuredWidth();
        }
    }

    private void removeNonVisibleItems(final int dx) {
        View child = getChildAt(0);
        while (child != null && child.getRight() + dx <= 0) {
            mDisplayOffset += child.getMeasuredWidth();
            mRemovedViewQueue.offer(child);
            removeViewInLayout(child);
            mLeftViewIndex++;
            child = getChildAt(0);

        }

        child = getChildAt(getChildCount() - 1);
        while (child != null && child.getLeft() + dx >= getWidth()) {
            mRemovedViewQueue.offer(child);
            removeViewInLayout(child);
            mRightViewIndex--;
            child = getChildAt(getChildCount() - 1);
        }
    }

    private void positionItems(final int dx) {
        if (getChildCount() > 0) {
            mDisplayOffset += dx;
            int left = mDisplayOffset;
            for (int i = 0; i < getChildCount(); i++) {
                View child = getChildAt(i);
                int childWidth = child.getMeasuredWidth();
                child.layout(left, 0, left + childWidth,
                        child.getMeasuredHeight());
                left += childWidth + child.getPaddingRight();
            }
        }
    }
    //
//	public synchronized void scrollToAndPos(int x, int position) {
//
//		mListWidth = new ArrayList<Integer>(this.getChildCount());
////		mMaxWidth = 0;
//		for(int i=0; i<this.getChildCount(); i++){
//			mListWidth.add(this.getChildAt(i).getWidth());
////			mMaxWidth += this.getChildAt(i).getWidth();
//		}
//		int w = SysUtil.getW(mContext);
//		int pX = 0;
//		int pNext = 0;
//		if(position > 0){
//			for(int i=0; i<position && i<mListWidth.size(); i++){
//				pX += mListWidth.get(i);
//			}
//			if( position < mListWidth.size())
//				pNext = pX + this.getChildAt(position).getWidth();
//		}
////		int maxWidth = this.getChildCount() * this.getWidth();
//		if (pX <= 0) {
//			pX = 0;
//		}
//		if (pX > this.getWidth()) {
//			pX = this.getWidth() - w;
//		}
////		if (pX > mMaxWidth) {
////		pX = mMaxWidth;
////	}
//		int scroll = 0;
//		if(x > pX){
//			if( x+w < pNext){
//				scroll = x+w-pNext;
//			}else{
//				scroll = pX;
//			}
//		}else{
//			if(pNext > x + w){
//				scroll = pNext - w;
//			}else{
//				scroll = x;
//			}
//		}
//		EMLog.d(this.getClass().getName()
//				, "pX="+pX + ",position="+position
//				+ ",x=" + x + ",pNext=" + pNext + ",scroll=" + scroll);
//		scrollTo(scroll);
//	}
    public synchronized void scrollTo(int x) {
        mScroller.startScroll(mNextX, 0, x - mNextX, 0);
        requestLayout();
    }

    @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
        boolean handled = super.dispatchTouchEvent(ev);
        handled |= mGesture.onTouchEvent(ev);
        return handled;
    }

    protected boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
                              float velocityY) {
        synchronized (MemberListView.this) {
            mScroller.fling(mNextX, 0, (int) -velocityX, 0, 0, mMaxX, 0, 0);
        }
        requestLayout();

        return true;
    }

    protected boolean onDown(MotionEvent e) {
        mScroller.forceFinished(true);
        return true;
    }

    private GestureDetector.OnGestureListener mOnGesture = new GestureDetector.SimpleOnGestureListener() {

        @Override
        public boolean onDown(MotionEvent e) {
            return MemberListView.this.onDown(e);
        }

        @Override
        public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
                               float velocityY) {
            return MemberListView.this
                    .onFling(e1, e2, velocityX, velocityY);
        }

        @Override
        public boolean onScroll(MotionEvent e1, MotionEvent e2,
                                float distanceX, float distanceY) {

            synchronized (MemberListView.this) {
                mNextX += (int) distanceX;
            }
            requestLayout();

            return true;
        }

        @Override
        public boolean onSingleTapConfirmed(MotionEvent e) {
            for (int i = 0; i < getChildCount(); i++) {
                View child = getChildAt(i);
                if (isEventWithinView(e, child)) {
                    if (mOnItemClicked != null) {
                        mOnItemClicked.onItemClick(MemberListView.this,
                                child, mLeftViewIndex + 1 + i,
                                mAdapter.getItemId(mLeftViewIndex + 1 + i));
                    }
                    if (mOnItemSelected != null) {
                        mOnItemSelected.onItemSelected(MemberListView.this,
                                child, mLeftViewIndex + 1 + i,
                                mAdapter.getItemId(mLeftViewIndex + 1 + i));
                    }
                    break;
                }

            }
            return true;
        }

        @Override
        public void onLongPress(MotionEvent e) {
            int childCount = getChildCount();
            for (int i = 0; i < childCount; i++) {
                View child = getChildAt(i);
                if (isEventWithinView(e, child)) {
                    if (mOnItemLongClicked != null) {
                        mOnItemLongClicked.onItemLongClick(
                                MemberListView.this, child, mLeftViewIndex
                                        + 1 + i,
                                mAdapter.getItemId(mLeftViewIndex + 1 + i));
                    }
                    break;
                }

            }
        }

        private boolean isEventWithinView(MotionEvent e, View child) {
            Rect viewRect = new Rect();
            int[] childPosition = new int[2];
            child.getLocationOnScreen(childPosition);
            int left = childPosition[0];
            int right = left + child.getWidth();
            int top = childPosition[1];
            int bottom = top + child.getHeight();
            viewRect.set(left, top, right, bottom);
            return viewRect.contains((int) e.getRawX(), (int) e.getRawY());
        }
    };

}
